In connection with the production, for example, of aircraft structural components a multitude of riveted connections are required, for example for connecting a cross girder or spar to a rib of an aircraft fuselage component. A respective multitude of holes must be drilled through these components for the riveted connections. Conventionally, one of the components to be connected with another component is provided with predrilled holes and these predrilled holes are used as a template for drilling corresponding holes into one or more further components.
Manually held power tools such as electric drills pose a problem, particularly in connection with the assembly operation of structural components having a large volume such as an aircraft fuselage, because these tools must not only be held in different working locations, the tools must also be held in precise positions so that, for example, drilled holes are accurately aligned with each other for the riveting operation. Nonaligned holes prevent the insertion of a rivet. The problem is magnified when the working locations are hard to access and/or when the power tools or machining tools are of substantial weight and still must be handheld and guided into the proper position. Thus, for example the structural assembly of an aircraft fuselage requires the performance of clamping, drilling and riveting in positions that require the assembly worker to assume different working positions, whereby the assembly worker must exert him or herself in handling these power tools, particularly when the power tools are heavy. Thus, in ergonomic terms, work of this type frequently reaches the limits of human capacity. Furthermore, in connection with such assembly operations a plurality of steps must be performed. These steps are freely conducted and are strength consuming. Such steps involve following the predrilling, the disconnection of the structural components, a deburring of the drilled holes, the application of caulking and then realigning the structural components, temporarily securing the components to each other and finish drilling the components. All these steps are quite time consuming and leave room for improvement, particularly with regard to optimizing these working steps in an ergonomic sense.
German Patent Publication DE 196 39 122, corresponding to U.S. Pat. No. 5,961,258 discloses an apparatus for clamping and drilling. The known apparatus comprises a base body carrying a clamping member and a drill section. The clamping member comprises a clamping bail which is movable together with a clamping element axially and against the feed advance direction from an open starting position into a clamping position. The drill section comprises a power drill and is operatively connected with the clamping member through a clamping piston cylinder device. Following the positioning of a drill bit tip in a predrilled hole, a starting button is pressed, whereby the components are automatically clamped to each other and the drilling operation is started. In many situations the working space is not available for the apparatus that combines the functions of clamping and drilling. As a result, the known clamping drilling machine cannot be properly positioned and hence cannot be used or its use becomes very difficult for the worker.